Rear Brakes - Knocking Noise

[pgc520]

Advice please, having passed the MOT and taken the car for a run, when the brakes are applied the rear brakes make a knocking sound. I have looked at shoes and they are installed the rights way round. I have cleaned the drums but cannot identify where the noise is coming from ?

Any ideas

Andrew

[mike.perry]

Which side or both? Are you sure that it is not a chipped tooth on the diff?

[pgc520]

Mike

why would a chipped tooth make a noise when the brakes are applied ? The axle makes no noise when under load, its only when the brakes are applied.

Andrew

[MarkyB]

Check the condition of the U bolts and the brackets between the rear springs and the axle.

[mike.perry]

Just eliminating possibilities
If you apply the handbrake whilst moving?

[beero]

As Mike says, does it click when handbrake applied? Does it click in reverse when braking?
Any clicks when brakes applied whilst stationary?
Jack it up on axle stands and run it in gear and apply the brakes with the wheels in the air.
Might help you to see/hear what is clicking.

[Annie_1952]

Hi, We had both knocking and squeaking on the back axle and it took ages to find out what it was.
In our case we found the new springs on the rear brakes were slightly bigger in diameter than the original ones and they were just catching on the hub where the bearings were. My husband carefully machined about 1/8" chamfer off the rough casting and this sorted it.
If you have driven it a couple of miles when its knocking (if its safe to do so), take it apart and you will see where it has marked it. Or you can paint the inside of the hubs, go for a short drive and see where its knocked the paint off.
We tried all sorts before finding this, hope you soon get sorted.
Good luck.

[pgc520]

Thanks for the suggestions!

U bolts re tightened - same

No knocking noise until brakes applied, only from rear axle.

Am wondering if new shoes are correct, does any one haev a photo of the rear shoes fitted so that I can see if thats what is wrong!

Thanks

Andrew


As Mike says, does it click when handbrake applied? Does it click in reverse when braking?
Any clicks when brakes applied whilst stationary?
Jack it up on axle stands and run it in gear and apply the brakes with the wheels in the air.
Might help you to see/hear what is clicking.

[mike.perry]

Back brake shoes are the same as rest of Minor rears with 1 cut out on 1 shoe to fit the adjuster. Try filing a champher on the leading edges of the shoes
I had a clicking noise but that was a wheel stud screwed in too far, you have bolts?
Are your wheels tight on the bolts? What size bolt heads have you got? 3/8 Whit or 5/8 A/F?
Are the drums tight on the half shaft splines or is there backlash?

[pgc520]

Mike,

I have stripped down a spare mm Axel to see what the differences are, it has the behive springs fitted. Were these fitted to the rear axel right from the start ?

Andrew

[mike.perry]

I never bother with the beehive springs, are your return springs fitted correctly?
Diagnosis would be a lot easier if you could email the sound!
Did you check the wheel bolts as per my previous posting?

[pgc520]

Mike,

using the old shoes it seems that the on the new ones the braking material was further back, so i did as u suggested and smoother the end of the shoes. Problem solved.

A [frame][/frame]